Jose Mourinho’s decision to exclude Diego Costa from Chelsea’s starting line-up for the 0-0 draw at White Hart Lane was surely about more than tactics.

Costa’s supposed reluctance to warm-up with his team-mates, combined with a petulant lob of his bib towards Mourinho at the end of the game, suggests their relationship is far from perfect.

But it was nevertheless a significant decision to play Eden Hazard up front instead. Mourinho was essentially going strikerless for this game, and it’s worth remembering that one of the few times Hazard had previously been fielded as a lone striker was in Roberto Di Matteo’s final game in charge, a 3-0 defeat at Juventus in November 2012. When the experiment didn’t work, Di Matteo was fired.

Get in the hole

With a system of two midfield players and one No.10, I demand a lot from a No.10. I like a No.10 to score goals. I like a No.10 to get in the box

- Jose Mourinho

Hazard was sensational last season from the left, cutting inside and contributing both goals and assists regularly. The problem with his positioning on that side, however, is his lack of defensive contribution, which was most notable during Chelsea’s Champions League semi-final exit to Atletico Madrid the previous campaign – Diego Simeone’s side scored two crucial away goals when Juanfran burst past Hazard easily. The following campaign Hazard put in more effort, but it still wasn’t entirely perfect.

Mourinho had grown accustomed to this situation from his time with Real Madrid, when he essentially built a system around the fact Cristiano Ronaldo didn’t track back either.

Usually, however, Mourinho has accommodated players like this as his No.10 – Wesley Sneijder at Inter Milan, for example – and it’s a little surprising that Hazard hasn't been used there.

Mourinho has criticised Hazard in the past for a lack of defensive effort

Intriguingly, Mourinho outlined his reasons last week.

“We have different concepts of No.10, me and him,” said Mourinho. “For me a No.10 does a lot of things, with the ball and without the ball. So for me a No.10 is a very special player in my team.

"With a system of two midfield players and one No.10, I demand a lot from a No.10. I like a No.10 to score goals. I like a No.10 to get in the box. I like a No.10 to score goals like Oscar's against Maccabi Tel Aviv.

"A No.10 for me is an eight-and-a-half when the team loses the ball, and a nine-and-a-half when the team has the ball. Who is my perfect No.10? Sneijder and Deco. They could defend, get in the box and finish.”

Sneijder was a key figure of Inter's 2010 treble

But this is only partly true. Sneijder was clearly given a much freer role towards the end of Mourinho’s treble-winning season at Inter, with Samuel Eto’o and Goran Pandev, two converted forwards, forced to become extraordinarily deep wide midfielders in response. Deco was given a freer role when Porto played a No.10. And what about Mesut Ozil at Real Madrid? Was he really contributing defensively, or was he remaining in a good position to break and lead Madrid's devastating counter-attacks?

Defensive diligence

The most surprising aspect of Hazard’s game was when he sprinted back 50 yards to tackle Kyle Walker on the byline

Either way, Mourinho’s decision to field Hazard as the forward against Tottenham underlines the fact he doesn’t trust the Belgian as a No.10 – he could quite easily have fielded Oscar or Pedro as the forward, and put Hazard deeper.

The Belgian performed reasonably well in his unfamiliar role, however, and showed much more energy than we’ve witnessed from Costa in recent weeks. His willingness to receive the ball in various situations was particularly noticeable, as he covered the width of the penalty area in an attempt to collect possession.

Hazard probably didn’t showcase his pace in behind the defence often enough, and the inevitable problem was that Chelsea simply didn’t have a reliable penalty-box presence. Hazard only received two passes inside the box – although one of these produced a fine volley that forced Hugo Lloris into an excellent save.

Besides, when receiving the ball in deeper positions, he created two decent chances by switching the ball left. It was a lively all-round performance, and probably more than a moody Costa would have contributed.

The most surprising aspect of Hazard’s game, however, was when he sprinted back 50 yards to tackle Kyle Walker on the byline. That’s the type of defensive effort we don’t usually see from him, even when he’s literally playing as a left winger, and suggests Mourinho’s criticism has convinced him to up his game and put in more effort without the ball. If that’s the case, maybe Mourinho will experiment with him as a No.10 too. With a disciplined midfield behind him, there’s no reason Hazard can’t shine in his favoured role.